Certain products consist of a plurality of ingredients, usually either liquid or powder, which advantageously should be mixed together just prior to actual use, but the ingredients of which should, for convenience of use, be furnished and sold in a single package or container. The present invention is especially adapted for use with two or three ingredients or substances which have extended shelf life when not mixed, but which must be used relatively soon after mixture to prevent deterioration. One example, in the pharmaceutical field, are certain types of local anesthetics, ingredients of which, if mixed just prior to actual administration to the patient, provide the advantages of faster onset of the anesthetic effect, a deeper anesthetic effect, and longer duration of the anesthetic effect. One such anesthetic is Lidocaine, which should be mixed with a buffering agent, such as NaHCO.sub.3 just prior to administration. There are many examples of this need in the pharmaceutical field. A number of injectable medicaments are stable for only short periods of time once they are in solution, such as when a dry ingredient is mixed with a diluent solution. There are many examples of this need in fields other than pharmaceutical, such as in the case of epoxy adhesives, cleansing solutions, various cosmetics and hair dyes. Conventional hair dyes, for example, employ a peroxide solution or the like, with which one or more pigmented solutions are mixed for immediate application to the hair, the color being determined by the make-up of the pigmented solutions. The provision of a container compartmented to contain each of the ingredients in its own compartment, but permitting intermixture of the ingredients whenever desired would obviously be useful and advantageous.
Certain prior art has made steps in this direction. Perhaps most notably, necked bottles have been provided with a plunger disposed slidably in the neck to seal it, and a stopper sealed in a restriction of the bottle disposed intermedite its ends. Different ingredients may thus be stored in the bottle compartments respectively above and below the stopper, and when it is desired to use the mixed ingredients, the stopper may be dislodged by pressing inwardly on the plunger, which exerts hydrostatic force through the liquid in the top compartment to dislodge the stopper into the bottom compartment. This concept has the disadvantage that it requires the top compartment to be substantially full, in order that the plunger may exert the necessary hydrostatic force to dislodge the stopper. This in turn limits the flexibility of application of the device, requiring compartments, particularly top comparnents, carefully designed to contain only the amount of liquid required for an individual dosage, in the case of pharmaceuiical products, or for a single usage in other fields of application. In the pharmaceutical field alone, this would require the manufacture and stocking of container bottles of an extremely large number of different sizes. Also, since it is virtually impossible to retrieve the dislodged stopper from the lower section of the bottle, the device is almost necessarily a single-use device, not capable of refilling and reuse. Another class of prior art utilizes compartmented bottles with the compartments divided from each other by diaphragms capable of being ruptured, and means such as plungers or the like for mechanically rupturing said diaphragms. Such devices are also single-use, non-reusable devices, and together with devices of the previously mentioned stopper type, do not allow control of the rate of intermixture of the ingredients, nor permit control of the order of intermixture if there are more than two ingredients to be mixed. Both of the latter named capabilities are important under many circumstances.